MMP3 and TIMP1 variants contribute to chronic periodontitis and may be implicated in disease progression

Aim Matrix metalloproteinases (MMPs) play a key role in the tissue destruction characteristic of chronic periodontitis. The purpose of this study was to investigate the association of MMP and TIMP polymorphisms with chronic periodontitis in two populations. Material and Methods A total of 34 polymorphisms spanning 12 MMP and 2 TIMP genes were genotyped in 401 individuals from Brazil (99 cases with chronic periodontitis and 302 controls), and 274 individuals from the US (70 cases and 204 controls). Individuals were considered cases if presenting at least three teeth exhibiting sites of clinical attachment loss =5 mm in two different quadrants. Controls were characterized by absence of clinical attachment loss and no sites with probing depth >3 mm. MMP3 and TIMP1 mRNA expression was evaluated in healthy and diseased periodontal tissues. Results TIMP1 showed association with chronic periodontitis in the Brazilian population (for rs5906435, p = 0.0004), whereas MMP3 showed association in the US population (for rs679620, p = 0.0003; and rs650108, p = 0.002) and in the Brazilian population (for rs639752, p = 0.005). MMP3 and TIMP1 mRNA expression was significantly higher in diseased tissues when compared to control tissues. Conclusions Our results further support a role for variations in MMP3 in chronic periodontitis and report a novel association with TIMP1. These genes may be considered additional candidate genes for chronic periodontitis.

Increased levels of Porphyromonas gingivalis are associated with ischemic and hemorrhagic cerebrovascular disease in humans: an in vivo study

Objective: This study investigated the role of periodontal disease in the development of stroke or cerebral infarction in patients by evaluating the clinical periodontal conditions and the subgingival levels of periodontopathogens. Material and Methods: Twenty patients with ischemic (I-CVA) or hemorrhagic (H-CVA) cerebrovascular episodes (test group) and 60 systemically healthy patients (control group) were evaluated for: probing depth, clinical attachment level, bleeding on probing and plaque index. Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans were both identified and quantified in subgingival plaque samples by conventional and real-time PCR, respectively. Results: The test group showed a significant increase in each of the following parameters: pocket depth, clinical attachment loss, bleeding on probing, plaque index and number of missing teeth when compared to control values (p<0.05, unpaired t-test). Likewise, the test group had increased numbers of sites that were contaminated with P. gingivalis (60%x10%; p<0.001; chi-squared test) and displayed greater prevalence of periodontal disease, with an odds ratio of 48.06 (95% CI: 5.96-387.72; p<0.001). Notably, a positive correlation between probing depth and the levels of P. gingivalis in ischemic stroke was found (r=0.60; p=0.03; Spearman's rank correlation coefficient test). A. actinomycetemcomitans DNA was not detected in any of the groups by conventional or real-time PCR. Conclusions: Stroke patients had deeper pockets, more severe attachment loss, increased bleeding on probing, increased plaque indexes, and in their pockets harbored increased levels of P. gingivalis. These findings suggest that periodontal disease is a risk factor for the development of cerebral hemorrhage or infarction. Early treatment of periodontitis may counteract the development of cerebrovascular episodes.

Newly forming bone graft: a novel surgical approach to the treatment of denuded roots

Many techniques have been proposed for root coverage. However, none of them presents predictable results in deep and wide recessions. Objective: The aim of this case series report is to describe an alternative technique for root coverage at sites showing deep recessions and attachment loss >4 mm at buccal sites. Material and Methods: Four patients presenting deep recession defects at buccal sites (>= 4 mm) were treated by the newly forming bone graft technique, which consists in the creation of an alveolar socket at edentulous ridge and transferring of granulation tissue present in this socket to the recession defect after 21 days. Clinical periodontal parameters, including recession depth (RD), probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), plaque index (PI) and keratinized gingiva width (KGW) were evaluated by a single examiner immediately before surgery and at 1, 3, 6 and 9 months postoperatively. Results: All cases showed reduction in RD and PD, along with CAL gain, although no increase in KGW could be observed. These findings suggest that the technique could favor periodontal regeneration along with root coverage, especially in areas showing deep recessions and attachment loss.

Potential of Bioactive Glass Particles of Different Size Ranges to Affect Bone Formation in Interproximal Periodontal Defects in Dogs

Background: The aim of this study was to compare the potential of bioactive glass particles of different size ranges to affect bone formation in periodontal defects, using the guided tissue regeneration model in dogs. Methods: In six dogs, 2-wall intrabony periodontal defects were surgically created and chronified on the mesial surfaces of mandibular third premolars and first molars bilaterally. After 1 month, each defect was randomly assigned to treatment with bioabsorbable membrane in association with bioactive glass with particle sizes between 300 and 355 mu m (group 1) or between 90 and 710 mu m (group 2), membrane alone (group 3), or negative control (group 4). The dogs were sacrificed 12 weeks after surgeries, and histomorphometric measurements were made of the areas of newly formed bone, new mineralized bone, and bioactive glass particle remnants. Results: With regard to the area of bioactive glass particle remnants, there was a statistically significant difference between groups 1 and 2, favoring group 1. There were greater areas of mineralized bone in groups 1 and 2 compared to groups 3 and 4 (P<0.05). Conclusion: The bioactive glass particles of small size range underwent faster resorption and substitution by new bone than the larger particles, and the use of bioactive glass particles favored the formation of mineralized bone. J Periodontol 2009;80:808-815.

Application of an active attachment model as a high-throughput demineralization biofilm model

Objectives: To investigate the potential of an active attachment biofilm model as a highthroughput demineralization biofilm model for the evaluation of caries-preventive agents. Methods: Streptococcus mutans UA159 biofilms were grown on bovine dentine discs in a highthroughput active attachment model. Biofilms were first formed in a medium with high buffer capacity for 24 h and then subjected to various photodynamic therapies (PACT) using the combination of Light Emitting Diodes (LEDs, Biotable (R)) and Photogem (R). Viability of the biofilms was evaluated by plate counts. To investigate treatment effects on dentine lesion formation, the treated biofilms were grown in a medium with low buffer capacity for an additional 24 h. Integrated mineral loss (IML) and lesion depth (LD) were assessed by transversal microradiography. Calcium release in the biofilm medium was measured by atomic absorption spectroscopy. Results: Compared to the water treated control group, significant reduction in viability of S. mutans biofilms was observed when the combination of LEDs and Photogem (R) was applied. LEDs or Photogem (R) only did not result in biofilm viability changes. Similar outcomes were also found for dentine lesion formation. Significant lower IML and LD values were only found in the group subjected to the combined treatment of LEDs and Photogem (R). There was a good correlation between the calcium release data and the IML or LD values. Conclusions: The high-throughput active attachment biofilm model is applicable for evaluating novel caries-preventive agents on both biofilm and demineralization inhibition. PACT had a killing effect on 24 h S. mutans biofilms and could inhibit the demineralization process. (C) 2011 Elsevier Ltd. All rights reserved.

Ethanol consumption enhances periodontal inflammatory markers in rats

Objective: The aim of this study was to assess the short term effect of ethanol administration on periodontal disease in rats. Design: Rats received either ethanol 2 g/kg or water by gastric gavage twice a day. On the fifth day ligatures were tied around the molars of half of the rats to induce periodontitis. After 7 days gingival tissue was removed and assayed for inflammatory markers. Finally, hemi-mandibles were extracted to evaluate bone loss by histomorphometrical techniques. Results: The experimental periodontitis increased significantly the mRNA expression (p < 0.001) and activity (p < 0.001) of inducible nitric oxide synthase (iNOS) in the gingival tissue, whilst short time ethanol administration increased iNOS activity (p < 0.05) and produced an additive effect on iNOS mRNA expression augmented by periodontitis (p < 0.01). The short time ethanol administration also potentiated the periodontitis stimulatory effect on the mRNA expression of interleukin (IL)-1 beta (p < 0.01 and p < 0.001, in semi-quantitative and real time PCR, respectively) and on the height of periodontal ligament (p < 0.05). However, the ligature-induced periodontitis, but not ethanol administration, increased the prostaglandin E-2 content (p < 0.05) and, diminished the alveolar bone volume (p < 0.05), as compared to sham rats. Conclusion: The present results suggest that ethanol consumption could represent a risk indicator for periodontal disease since augments the expression of inflammatory markers, in healthy rats, and increases them, at short term, during the illness. However, scale longitudinal investigation and more case-control studies are needed to confirm this statement. (C) 2012 Elsevier Ltd. All rights reserved.

MIF induces osteoclast differentiation and contributes to progression of periodontal disease in mice

Periodontal disease (PD) is a chronic inflammatory and alveolar bone destructive disease triggered by microorganisms from the oral biofilm. Oral inoculation of mice with the periodontopathogen Aggregatibacter actinomycetemcomitans (Aa) induces marked alveolar bone loss and local production of inflammatory mediators, including Macrophage Migration Inhibitory Factor (MW). The role of MW for alveolar bone resorption during PD is not known. In the present study, experimental PD was induced in BALB/c wild-type mice (WT) and MW knockout mice (MIF-/-) through oral inoculation of Aa. Despite enhanced number of bacteria, MIF-/- mice had reduced infiltration of TRAP-positive cells and reduced alveolar bone loss. This was associated with decreased neutrophil accumulation and increased levels of IL-10 in periodontal tissues. TNF-alpha production was similar in both groups. In vitro, LPS from Aa enhanced osteoclastic activity in a MIF-dependent manner. In conclusion, MIF has role in controlling bacterial growth in the context of PD but contributes more significantly to the progression of bone loss during PD by directly affecting differentiation and activity of osteoclasts. (C) 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Influence of combined oral contraceptives on the periodontal condition

Most studies investigating the impact of oral contraceptives have been performed some years ago, when the level of sexual hormones was greater than the actual formulations. Objective: The aim of this study was to evaluate the effects of current combined oral contraceptives (COC) on periodontal tissues, correlating the clinical parameters examined with the total duration of continuous oral contraceptive intake. Material and methods: Twenty-five women (19-35 years old) taking combined oral contraceptives for at least 1 year were included in the test group. The control group was composed by 25 patients at the same age range reporting no use of hormone-based contraceptive methods. Clinical parameters investigated included pocket probing depth (PD), clinical attachment level (CAL), sulcular bleeding index (SBI) and plaque index (PI.I). Data were statistically evaluated by unpaired t test, Pearson's correlation test and Spearman's correlation test. Results: The test group showed increased PD (2.228+/-0.011 x 2.154+/-0.012; p<0.0001) and SBI (0.229+/-0.006 x 0.148+/-0.005, p<0.0001) than controls. No significant differences between groups were found in CAL (0.435+/-0.01 x 0.412+/-0.01; p=0.11). The control group showed greater PI.I than the test group (0.206+/-0.007 x 0.303+/-0.008; p<0.0001). No correlation between the duration of oral contraceptive intake, age and periodontal parameters was observed. Conclusions: These findings suggest that the use of currently available combined oral contraceptives can influence the periodontal conditions of the patients, independently of the level of plaque accumulation or total duration of medication intake, resulting in increased gingival inflammation.

Non-inflammatory destructive periodontal disease: a clinical, microbiological, immunological and genetic investigation

Periodontitis comprises a group of multifactorial diseases in which periodontopathogens accumulate in dental plaque and trigger host chronic inflammatory and immune responses against periodontal structures, which are determinant to the disease outcome. Although unusual cases of non-inflammatory destructive periodontal disease (NIDPD) are described, their pathogenesis remains unknown. A unique NIDPD case was investigated by clinical, microbiological, immunological and genetic tools. The patient, a non-smoking dental surgeon with excessive oral hygiene practice, presented a generalized bone resorption and tooth mobility, but not gingival inflammation or occlusion problems. No hematological, immunological or endocrine alterations were found. No periodontopathogens (A. actinomycetemcomitans, P. gingivalis, F. nucleatum and T. denticola) or viruses (HCMV, EBV-1 and HSV-1) were detected, along with levels of IL-1 beta and TNF-alpha in GCF compatible with healthy tissues. Conversely ALP, ACP and RANKL GCF levels were similar to diseased periodontal sites. Genetic investigation demonstrated that the patient carried some SNPs, as well HLA-DR4 (*0404) and HLA-B27 alleles, considered risk factors for bone loss. Then, a less vigorous and diminished frequency of toothbrushing was recommended to the patient, resulting in the arrest of alveolar bone loss, associated with the return of ALP, ACP and RANKL in GCF to normality levels. In conclusion, the unusual case presented here is compatible with the previous description of NIDPD, and the results that a possible combination of excessive force and frequency of mechanical stimulation with a potentially bone loss prone genotype could result in the alveolar bone loss seen in NIDPD.

Persistent Periodontal Disease Hampers Anti-Tumor Necrosis Factor Treatment Response in Rheumatoid Arthritis

Objective: This study aimed to evaluate prospectively the influence and the evolution of periodontal disease (PD) in rheumatoid arthritis (RA) patients submitted to anti-tumor necrosis factor (TNF) therapy. Methods: Eighteen patients with RA (according to the American College of Rheumatology criteria) were assessed for PD before (BL) and after 6 months (6M) of anti-TNF treatment: 15 infliximab, 2 adalimumab, and 1 etanercept. Periodontal assessment included plaque and gingival bleeding indices, probing pocket depth, cementoenamel junction, and clinical attachment level. Rheumatologic evaluation was performed blinded to the dentist's assessment: demographic data, clinical manifestations, and disease activity (Disease Activity Score using 28 joints [DAS28], erythrocyte sedimentation rate [ESR], and C-reactive protein [CRP]). Results: The median age and disease duration of patients with RA were 50 years (25-71 y) and 94% were female. Periodontal disease was diagnosed in 8 patients (44.4%). Comparing BL to 6M, periodontal parameters in the entire group remained stable (P > 0.05) throughout the study (plaque and gingival bleeding indices, probing pocket depth, cementoenamel junction, and clinical attachment level), whereas an improvement in most analyzed RA parameters was observed in the same period: DAS28 (5.5 vs. 3.9, P = 0.02), ESR (21 vs. 12.5 mm/first hour, P = 0.07), and CRP (7.8 vs. 2.8 mg/dL, P = 0.25). Further analysis revealed that this improvement was restricted to the group of patients without PD (DAS28 [5.5 vs. 3.6, P = 0.04], ESR [23.0 vs. 11.5 mm/first hour, P = 0.008], and CRP [7.4 vs. 2.1, P = 0.01]). In contrast, patients with PD had lack of response, with no significant differences in disease activity parameters between BL and 6M: DAS28 (5.2 vs. 4.4, P = 0.11), ESR (17.0 vs. 21.0, P = 0.56), and CRP (9.0 vs. 8.8, P = 0.55). Conclusions: This study supports the notion that PD may affect TNF blocker efficacy in patients with RA. The possibility that a sustained gingival inflammatory state may hamper treatment response in this disease has high clinical interest because this is a treatable condition.

Quantitative detection of Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa in human oral epithelial cells from subjects with periodontitis and periodontal health

Epithelial cells in oral cavities can be considered reservoirs for a variety of bacterial species. A polymicrobial intracellular flora associated with periodontal disease has been demonstrated in buccal cells. Important aetiological agents of systemic and nosocomial infections have been detected in the microbiota of subgingival biofilm, especially in individuals with periodontal disease. However, non-oral pathogens internalized in oral epithelial cells and their relationship with periodontal status are poorly understood. The purpose of this study was to detect opportunistic species within buccal and gingival crevice epithelial cells collected from subjects with periodontitis or individuals with good periodontal health, and to associate their prevalence with periodontal clinical status. Quantitative detection of total bacteria and Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis in oral epithelial cells was determined by quantitative real-time PCR using universal and species-specific primer sets. Intracellular bacteria were visualized by confocal microscopy and fluorescence in situ hybridization. Overall, 33 % of cell samples from patients with periodontitis contained at least one opportunistic species, compared with 15 % of samples from healthy individuals. E. faecalis was the most prevalent species found in oral epithelial cells (detected in 20.6 % of patients with periodontitis, P = 0.03 versus healthy individuals) and was detected only in cells from patients with periodontitis. Quantitative real-time PCR showed that high levels of P. aeruginosa and S. aureus were present in both the periodontitis and healthy groups. However, the proportion of these species was significantly higher in epithelial cells of subjects with periodontitis compared with healthy individuals (P = 0.016 for P. aeruginosa and P = 0.047 for S. aureus). Although E. faecalis and P. aeruginosa were detected in 57 % and 50 % of patients, respectively, with probing depth and clinical attachment level ≥6 mm, no correlation was found with age, sex, bleeding on probing or the presence of supragingival biofilm. The prevalence of these pathogens in epithelial cells is correlated with the state of periodontal disease.